The invention lies in the field of appliances. The invention relates to a drive apparatus for a front-loading laundry treatment machine having a laundry drum that is mounted at least approximately horizontally and in a supporting part through a shaft and that is driven directly by a motor that is disposed on its rear face and whose magnetic poles that are disposed on the rotor, are externally opposite the laminated cores that are provided on the stator to accommodate field windings, with a minimal air gap.
A drive apparatus is disclosed in German Published, Non-Prosecuted Patent Application DE 195 47 745 A1, corresponding to U.S. Pat. No. 5,862,686 to Skrippek. In the prior art drive apparatus, the stator is mounted on a stiff supporting part that, for its part, is connected to the rear wall of a suds container. The supporting part has a central bearing sleeve for the shaft of the laundry drum and for a hub, which surrounds the shaft, of the rotor. The hub is fitted with a bell-like flange that points toward the suds container and on whose inner circumference magnetic poles are distributed. The magnetic poles are externally opposite laminated cores, which are distributed on the stator and are provided for accommodating field windings of the stator, with a minimal air gap.
It is accordingly an object of the invention to provide a drive apparatus for a front-loading laundry treatment machine that overcomes the hereinafore-mentioned disadvantages of the heretofore-known devices of this general type and that has a simple, compact construction.
With the foregoing and other objects in view, there is provided, in accordance with the invention, a drive apparatus for a front-loading laundry treatment machine, including a support having a projection and a rear face, a shaft having a longitudinal axis, a laundry drum having a rear wall, the laundry drum mounted substantially horizontally on the support through the shaft, the rear wall having a bell-shaped depression with an inner circumference, the bell-shaped depression extending in a direction of the longitudinal axis and accommodating the projection, a motor having magnetic poles and a stator with field windings and laminated cores, the motor disposed on the rear face and directly driving the shaft, the laminated cores disposed on the projection, and the magnetic poles distributed on the inner circumference and disposed externally opposite the laminated cores to accommodate the field windings with an air gap therebetween.
According to the invention, the rear wall of the laundry drum has a bell-shaped depression that extends in the direction of the longitudinal axis of the shaft and on whose inner circumference, facing the shaft, the magnetic poles of the rotor are distributed, and, in that, the laminated cores of the stator are mounted on the supporting part that projects out of the depression.
The invention provides a drive apparatus that saves material and space. Because the laundry drum has an inward bulge, the drive motor is accommodated in the interior of the laundry drum. Accordingly, there is no need to provide any space for a flat motor, driving the laundry drum directly, or for a drive belt between the rear face of the laundry drum and the rear wall of the laundry treatment machine, that is to say, of the laundry dryer or of the washing machine.
In contrast to the prior art, there is no need to provide any additional components for accommodating the magnetic poles of the rotor and, in fact, the rear wall of the laundry drum is configured such that it accommodates the poles directly. Thus, there is no need for the complex construction of a flange that is, for example, bell-shaped, as is provided according to U.S. Pat. No. 5,862,686.
In accordance with another feature of the invention, there is provided a suds container and the support is part of the suds container.
In accordance with a further feature of the invention, part of the support is at the same time the bearing sleeve for the shaft of the laundry drum and is used as a stator support for accommodating the stator cores. Heat that is produced during operation of the motor is dissipated through the metallic and, thus, thermally highly conductive, rear wall of the laundry drum, and is used to heat the laundry or the washing suds or water.
Because the laundry drum is mounted close to the center of gravity, the configuration reduces the influence of any unbalance or of tumbling.
In accordance with an added feature of the invention, the suds container includes the rear face and the projection, the projection is a bell-shaped flange, and the laminated cores are disposed on the bell-shaped flange.
In accordance with an additional feature of the invention, the bell-shaped flange forms a bearing sleeve of the shaft.
In accordance with yet another feature of the invention, the supporting part is a metal casing, for example, an aluminum casting or a cast-iron casting.
In accordance with yet a further feature of the invention, the bell-shaped flange is a metal casting, for example, an aluminum casting or a cast-iron casting.
The motor is, for example, a reluctance motor, with the magnetic poles of the rotor being laminated iron sheets, or is an electronically commutated DC motor, with the poles being permanent magnets.
In accordance with yet an added feature of the invention, there is provided a seal disposed between the rear wall of the laundry drum and the rear wall of the suds container sealing the motor from laundry suds.
In accordance with yet an additional feature of the invention, the motor is a switched reluctance motor.
In accordance with again another feature of the invention, the magnetic poles are laminated iron sheets.
In accordance with again a further feature of the invention, there are provided laminated iron sheets forming the magnetic poles.
In accordance with again an added feature of the invention, the motor is an electronically commutated DC motor.
In accordance with again an additional feature of the invention, the magnetic poles are permanent magnets.
In accordance with still another feature of the invention, there are provided permanent magnets forming the magnetic poles.
In accordance with still a further feature of the invention, the laminated cores are at least one of segments and rings.
In accordance with still an added feature of the invention, the magnetic poles are at least one of segments and rings.
In accordance with still an additional feature of the invention, the laminated cores and the magnetic poles are opposite one another in a radial direction perpendicular to the longitudinal axis of the shaft.
In accordance with a concomitant feature of the invention, the laminated cores and the magnetic poles are opposite one another in a direction parallel to the longitudinal axis of the shaft.
Other features that are considered as characteristic for the invention are set forth in the appended claims.
Although the invention is illustrated and described herein as embodied in a drive apparatus for a front-loading laundry treatment machine, it is, nevertheless, not intended to be limited to the details shown because various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.
The construction and method of operation of the invention, however, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.